Searchlight



'Nov. 1, 1938. 1. A. YOST ET AL SEARCHLIGHT Filed Oct. 50, 1955 3Sheets-Sheet l Nov. 1, 1938. A. YosT ET AL SEARCHLIGHT Filed 001;. 30,1935 5 Sheets-Sheet 2 lNVEHTC-RS WITNESSES: W/Xm n.

M/K/arrz fiicaizj Nov. 1, 1938.

l. A. YOST ET AL SEARCHLIGHT Filed Oct. 50, 1935 5 Sheets-Sheet 3Patented Nov. 1, 1938 UNITED STATES PATENT OFFlCE Jacobi, Wilkinsburg,

Pa., assignors to Westinghouse Electric & Manufacturing Company,

East Pittsburgh, Pa.,

sylvania a corporation of Penn- Applicaticn October 30, 1935, Serial No.47,446

10 Claims.

The invention relates, generally, to searchlights, and, moreparticularly, to the construction of arc searchlights as regards thesupporting of the arc head mechanism or unit and the operating mechanismtherefor.

Heretofore, it has been the usual practice to support the arc headmechanism, comprising the electrode holders, feed rollers, etc., withinthe drum in the proper relation to the reflector by means of a suitablestandard or column secured to the bottom of the drum. Such forms ofsupport perform no useful function other than to support the arc headunit and are not sufliciently rigid and stable to maintain the arc headunit in the same position with respect to the reflector for all possiblepositions of the searchlight drum and under all operating conditions.

In addition, searchlights of large diameter have been usually designedwith a glass front made up of a plurality of segments of glass supportedand retained in the desired relationship by means of a suitable centerpiece and a plurality of brackets vertically disposed diametricallyacross the drum, leaving the joints formed by the abutting edges of theglass segments exposed to the direct light rays of the beam producinglight dispersion and thus a source of stray light.

It is, therefore, one of the primary purposes and objects of the presentinvention to provide for the elimination of the aforementioned defectsand disadvantages by utilizing a form of support for the arc headmechanism which will rigidly support it in fixed relation to thereflector under all operating conditions and which will function toeliminate light dispersion produced by the joints in the glass front.

A more specific object of the invention is to provide for supporting thearc head unit or mechanism by means of radially disposed brackets orstrips secured to the side walls of the drum in spaced relation and forutilizing the brackets both as conductors to carry current to the arcand as screens to block off the light from the joints between the glasssegments of the front cover.

Another object of the invention is to provide for utilizing thesupporting means for the arc head unit or mechanism for conductingcurrent to the arc head or the operating mechanism therefor, or both, asthe case may be.

A still further object of the invention is to provide for utilizing thetrunnion support of the drum as a compartment to house the operatingmechanism for the arc head, thus providing a closed compartment withoutthe use of a separate control casing or box attached to the outside ofthe drum.

Another object of the invention is to provide for utilizing the radialbrackets of the support for the arc head unit or mechanism inconjunction with the radial brackets of the front door or cover for thedrum for the purpose of effectively screening the radially disposedjoints between the glass segments of the door from the light produced bythe arc to eliminate stray light.

The general object of the invention is to provide a searchlightstructure which shall be simple and efficient in operation and which maybe readily manufactured, assembled and maintained.

These and other important objects and advantages of the invention willbecome more apparent from a reading of the following detaileddescription taken in conjunction with the drawings wherein,

Figure l is a front elevational view of a searchlight, with the frontdoor or cover removed, embodying the principal features of theinvention,

Fig. 2. is a side elevational view partially in section taken alonglines IIII of the structure of Fig. 1

Fig. 3 is a front elevational view of the front cover or door for thesearchlight structure of Figs. 1 and 2,

Fig. 4 is a view taken along lines IV-IV of Fig. 3

Fig. 5 is an enlarged top plan View, partially in section, of theSearchlight showing the manner in which the operating mechanism ismounted within the trunnion support, and

Fig. 6 is an enlarged side elevational view in cross section of thetrunnion assembly of Fig. 5.

In the preferred embodiment of the invention, the arc head unit ormechanism comprising the electrode holders, feed rollers, etc., issupported for movement along the longitudinal axis of the drum by meansof a supporting ring or bracket and a plurality of radial membersinterposed between the supporting bracket and the side walls of thedrum. The radial members may be equally spaced and positioned directlyopposite or behind certain ones of the joints between the glass segmentsof the front door in such manner that they cooperate with the radialsupports of the door to effectively screen all of the door joints fromthe light produced by the arc, the radial supports for the doorpreferably alternating in position with the radial support members ofthe arc head support.

The mechanism for operating the arc head is mounted'within one of thehollow trunnion supports and connected to the arc head mechanism bodyregardless of the drum position and does by means of suitable driveshafts and universal joints.

Certain ones of the radial members of the arc head support are utilizedas current conductors to carry current to the electrodes or theoperating mechanism, or both, as the case may be, thus eliminating theuse of separate conductors in the drum to complete the arc circuit.

Referring now to the drawings, there is shown in Figs. 1, 2 and 5 asearchlight drum 8, rotatably mounted for movement about a horizontalaxis on trunnion assemblies 9 and H3, in which the arc head unit H andoperating mechanism |2 therefor are mounted in accordance with theprinciples of the invention.

It is to be understood that since the details of construction of the archead unit I I and operating mechanism |2 do not in themselves constitutepart of the present invention, these elements have been illustrated in amore or less diagrammatic manner to illustrate the invention withoutunduly complicating the drawings. By way of example, the arc head unitmay be of the type that both rotates and feeds the positive electrode E3and which is actuated by the operating mechanism l2 by means of adetachable shaft connection M in a well known manner. The feed rollersl5 for controlling the movements of the negative electrode I6 maylikewise be driven through a similar shaft connection I! by theoperating mechanism l2.

In order to provide for supporting the arc head unit it within the drumin the proper relation to the reflector l8 and in a rigid manner bymeans which will eliminate stray light and perform other usefulfunctions as well, there is utilized an arrangement comprising asupporting bracket or ring L! and a plurality of radial members 2i to26, inclusive.

As will be observed, the arc head unit II in this instance is movablysupported within the supporting ring l9 by means of a plurality of sliderails or bars 21 through 30, which cooperate with suitable guide ways 3|formed on the inside of the ring I9. This permits the arc head to beadjusted along the longitudinal axis of the drum and enables it to bereadily removed for inspection and repair. The movements of the arc headmay be effected in any suitable manner such as by the actuating rod orshaft 32 and gears 33. The adjusting rod 32 may be operated in anysuitable or desired manner from without the drum in order thatadjustments of the arc head may be made while the light is in operation.

The radial members 2| through 26 are of relatively thin flat shapehaving their narrow edges exposed to the light source in order tointerfere as little as possible with the projected light. They aresuitably secured at their outer ends to the rim portion 34 of the drumand are secured to the support ring |9 at their inner ends. As shown inFig. 2, the radial members are projected or inclined outwardly in orderthat the supporting structure will not sag as the drum I is rotatedabout its horizontal axis.

As shown in Fig. 2, the rim portion 34 of the drum 8 is preferablyformed integrally with the side Walls thereof and extends inwardly inthe form of a flange. It provides an enlarged rim portion of such sizeas to reinforce the front opening of the drum in such a way as tostrengthen and increase the rigidity thereof.

It apparent that this construction is of such nature as to distributethe load to the rigid drum not subject the drum structure to aconcentrated strain at only one position.

The front door or cover 35 for the drum 8 is shown in Figs. 3 and 4 andcomprises gener ally a rim element 38 which may be hingedly secured tothe drum by means of suitable hinge lugs 3'! which are disposed tocooperate with the hinge lugs 38 on the drum. Clamping devices 39 areprovided on the drum for securing the door in a closed position.

In this instance, the door is made up of a plurality of glass segments4| which are clamped to the rim 36 by plates 42 and which are supportedby means of a center piece 43 secured to the rim 36 by means of radialmembers 46. In this instance, the glass portion of the door is made upof twelve segments forming an equal number of radial joints 4'|therebetween.

It has been observed that the joints 41 between the glass segments 4| ofthe door produce light dispersion which is the cause of a considerableamount of stray light. In order to provide for reducing the stray lightthus produced without the use of separate means for this purpose only,provision is made for utilizing the radial members of both the door andthe arc head supporting structure to effectively screen every joint fromthe projected light.

In this instance, since there are twelve joints to be protected, thusrequiring a total of twelve screening devices, six radial members areutilized in both the door and the arc head support, the radial members46 of the door alternating in position with those of the arc headsupport. It is apparent that the radial members 45 in the door structureare fixed in position directly opposite or behind alternate jointsbetween the glass segments and that the radial members of the arc headsupport are so positioned that when the door 35 is secured to the drumand in its closed position, they likewise are positioned directly behindthe remaining joints. Since all of the radial members are of thinconstruction, the total area thereof which is exposed to the projectedlight is so small as to be of no consequence. At the same time, thesemembers are of suflicient thickness to effectively screen the jointsfrom the projected light.

With a View to providing a housing for the operating mechanism I2 forthe arc head without utilizing a separate control box or housing securedto the outside of the drum as is the usual custom, provision is made inthis instance for utilizing one of the trunnion assemblies for thispurpose.

In this instance, the operating mechanism l2 which may be of anysuitable design is mounted within the trunnion assembly 9. Referring toFigs. and 6, it will be observed that the trunnion assembly 9 is soconstructed that it forms a compartment on the side of the drum. Thetrunnion member 5| in this instance is integral with a dome-shapedsupport member 52 which is suitably secured to the side of the drum. Thetrunnion 5| is supported by means of a suitable bearing 53 which iscarried in the trunnion housing 54 which, as shown in Fig. 1, is adaptedto be bolted or otherwise secured to one of the arms 55 of the trunnioncradle. A suitable opening 56 is provided in the drum opposite thetrunnion which may be covered by a plate 51 in order to enclose thecompartment thus formed. If desired, the operating mechanism may bemounted upon the plate 57 in order to facilitate in its removal from thecompartment. As shown, the trunnion is in the nature of a hollow shaftthrough which any additional control devices may be passed, if desired.The trunnion assembly l0 may be of the same construction as the trunnionassembly 9 and may be utilized to house other control devices.

In order to provide for carrying current to the arc head H and theoperating mechanism l2 therefor, provision is made for utilizing certainones of the radial members of the arc head support for this purpose. Inthis instance, it is assumed that the arc current also passes throughthe operating mechanism l2 and a circuit for accomplishing this purposeis illustrated. As shown, the radial members 2|, 23, 24 and 26 areinsulated by means of suitable insulating members 66 from the rim 34 andthe supporting ring IS. The current supply conductors while not shownmay be brought in through the arm 58 of the trunnion cradle andconnected to the terminals 59 and 6!, as shown. The internal circuit forthe drum may then be formed by connecting the supply terminals 59 and 6|to the radial members 2| and 26 by suitable shunts 62 and 63, byconnecting the radials 2| and 23 with a shunt 64 and by connecting eachof the radials 23 and 24 to the terminals 65 and 66 by means of shunts6i and 68. As shown in Fig. 2, the circuit is then completed through theare by connecting the radial member 24 to the positive electrode holderby means of a suitable shunt t9 and the radial member 26 to the negativeelectrode holder by means of a shunt TI. The terminals 65 and 63 aremounted upon the plate 51 which encloses the trunnion compartment andsuitable connections provided therefrom to those elements of theoperating mechanism which are to be subjected to the arc current.

It is to be understood that in case it is desired to conduct current tothe are only, radial members 2! and 26 may be used for this purpose.

In view of the foregoing description, it is apparent that the inventionembodies features and principles which are novel and of great utility inconnection with the construction of high intensity arc searchlightswhere the greatest efliciency obtainable is desired. The nature of thearc head supporting structure makes possible its use for the performanceof several functions thereby simplifying the construction to aconsiderable degree. Its use as a supporting means which is its primaryfunction provides for rigidly supporting the arc head mechanism. Itsauxiliary function in conjunction with the radial members of the door toeliminate stray light makes it unnecessary to provide separate means foreffecting this function. Its additional auxiliary function as a currentconductor for the are or the operating mechanism, or both eliminates thenecessity for placing separate current conductors within the drum.

Although a specific embodiment of the invention has been illustrated anddescribed, it will be obvious to those skilled in the art that variouschanges may be made in the details of construc tion such as in theproportion and the design of the several cooperating parts withoutdeparting from the principles herein set forth.

We claim as our invention:

1. A searchlight comprising a drum, a transparent cover thereforcomprising a plurality of segments of transparent material, an arc headmechanism, and a plurality of radially disposed members for supportingthe arc head mechanism from the sides of the drum, said radiallydisposed members being positioned directly opposite the joints betweenthe transparent segments of the cover.

2. A searchlight comprising a drum, a transparent cover thereforcomprising a plurality of segments of transparent material, and meanscomprising a plurality of radially disposed supporting members forsupporting the arc-head mechanism from the walls of the drum, saidsupporting members being positioned adjacent to every other one of thejoints between the segments between the transparent cover and the archead mechanism thereby to cast a shadow upon the joints and eliminatelight dispersion.

3. A searchlight comprising a drum, a door for the drum comprising aplurality of glass segments and radially disposed support memberspositioned adjacent a plurality of the joints between the segments, anarc head mechanism,and means including a plurality of radially disposedmembers for supporting the arc head from the walls of the drum, saidlast-named radial supports being positioned adjacent the remainder ofthe joints between the glass segments.

4. A searchlight comprising a drum, a door for the drum comprising aplurality of glass segments and radially disposed support memberspositioned adjacent a plurality of the joints between. the segments, anarc head mechanism, a bracket member for movably supporting the arc headmechanism, a plurality of radial members for supporting the bracketmember from the sides of the drum, said radial members being interposedbetween the radial support members for the door and adjacent the jointsbetween the glass segments.

5. A searchlight comprising a drum having an integral back portion and areinforcing ring portion around the edge of the front opening, an archead mechanism, a supporting bracket for the arc head mechanism, and aplurality of substantially equally spaced fiat shaped radial membersinterposed between the supporting bracket and the reinforcing ringportion of the drum for supporting the arc head mechanism.

6. A searchlight comprising a drum, supporting trunnions on oppositesides of the drum, an arc head mechanism, means including a plurality ofradially disposed current conducting members of fiat shape forsupporting the arc head mechanism from the side walls of the drum, powersupply terminals positioned within the drum adjacent one of saidsupporting trunnions, and means including at least two of said radialsupporting members for connecting the power supply terminals to the archead mechanism.

'7. A searchlight comprising a drum, supporting trunnions on oppositesides of the drum, an arc head mechanism, means including a plurality ofradially disposed current conducting members of fiat shape forsupporting the arc head mechanism from the side walls of the drum, powersupply terminals mounted within the drum adjacent one of said supportingtrunnions and movable therewith, means for connecting the outer ends oftwo of said radial supporting members to the power supply terminals, andmeans connecting the opposite ends of said radial supporting members tothe arc mechanism to provide for supplying current thereto.

8. A searchlight comprising a drum, an arc mechanism,electrically-operated means for actuating the arc mechanism, terminalmembers for said electrically operated means extending within the drum,power supply terminals mounted within the drum, means including aplurality of radially-disposed members for supporting the arc mechanismfrom the side walls of the drum, means for connecting the outer ends ofone pair of said supporting members to the power supply terminals, meansfor connecting the outer ends of another pair of said supporting membersto the terminal members of the electrically-operated means, means forconnecting the inner ends of one supporting member in each pair togetherto form a continuous conductor, and means for connecting the inner endsof the other radial members of each pair to the arc mechanism.

9. A searchlight comprising a drum, a transparent cover therefor havinga plurality of radial joints therein, an arc head mechanism, meansincluding a plurality of radially disposed members for supporting thearc head mechanism from the side walls of the drum, said supportingmembers being located within the drum and directly behind the radialjoints in the cover, power supply terminals within the drum, and meansincluding at least two of said radial supporting members for connectingthe power supply terminals to the arc head mechanism.

10. A searchlight comprising a drum, an arc head mechanism comprising apair of electrode holders, means including a plurality of relativelythin radial members for supporting the arc head mechanism from the wallsof the drum, a plurality of power supply terminals within the drum, aplurality of power consumption terminals within the drum, means forconnecting the outer ends of two pairs of adjacent radial members to thepower consumption and power supply terminals respectively, means forconnecting the inner ends of the radial member in each pair together,and flexible means for connecting the inner ends of the other radialmembers in each pair to the electrode holders.

IRVINE A. YOST. WILLIAM H. JACOBI.

